Republican presidential candidate Dr. Ben Carson is pausing his campaign events for two weeks to promote his new book, A More Perfect Union, and amplify his fundraising efforts just as front-runner Donald Trump widened his lead on Carson in two key primary states.

Carson is expected to make a brief book tour next week, visiting Oklahoma, Nebraska, Texas, Kansas, Missouri and Iowa, ABC reports. In the book, Carson highlights freedoms granted in the constitution and "what we the people can do to reclaim our constitutional liberties," as the subtitle states.

Although the book directly focuses on policy, his campaign wants to affirm that the book tour is completely unrelated to his campaign. Because it's illegal for candidates to use campaign resources for personal profit, Carson won't have his campaign staff at his side while touring, the Huffington Post reports.

"It's a question of co-mingling from the corporate standpoint to the Federal Election Commission standpoint, so it's just better to avoid any bad appearance," Carson's spokesman Doug Watts told ABC News.

Carson's campaign is likely trying to avoid the skepticism 2012 presidential candidate Newt Gingrich earned for tying his campaign with personal profit when he sold his book at various campaign events. "The story is the same virtually everywhere Gingrich goes: a political speech here, a book-signing there — often in the same place," Washington Post's Amy Gardner wrote in 2011.

Carson's last campaign event was on Oct. 2; his camp says Carson's next public campaign appearance will be the day of the third GOP presidential debate onOct. 28.